code: def test_main(self):
      mat_factory = CSRMatrixFactory()
      mat_factory[0, 0] = 4
      mat_factory[1, 5] = 3
      mat = mat_factory.get_csr_matrix()
      self.assertEqual(type(mat), csr_matrix)
      np.testing.assert_array_almost_equal(
          np.array([[4, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 3]]),
          mat.todense(),
      )
  
file_path: scattertext/scattertext/test/test_CSRMatrixTools.py
imports: from unittest import TestCase
  import numpy
  from scipy.sparse import csr_matrix
  import scattertext
  from scattertext.CSRMatrixTools import CSRMatrixFactory
label_desc: Use image node_id 1 for calling the TestCSRMatrixFactory obj's underlying member method code with example usage: obj.test_main() without return types